Should the "Wheesley" Engine be Changed?

[Mr. Peabody]

I'm sure some of you out there use it, but aside from its lower cost and reverse thrust capability the wheesley has no real advantages over the panther jet engine for use on low atmosphere jet planes. The panther is more fuel efficient, produces more thrust, and has less mass than the wheesley. So why would anyone use it? Does it just exist in the game so players in career mode can have an engine for their early aircraft? I'm curious to know what use it would have that the panther wouldn't be better at. In my opinion there should be more distinction between the wheesley and the panther, such as greater fuel efficiency or less mass.

[Snark]

1 hour ago, The Dunatian said:

Does it just exist in the game so players in career mode can have an engine for their early aircraft?

I'd say it's likely this.  It's the same deal as the OKTO probe core-- why would you ever use it once HECS is available?

There aren't a lot of KSP parts that become completely obsolete, which is one of the things I like about the design of the stock parts overall... but there are a few, and that's one of them.

[Aegolius13]

I thought the Wheesley had a tiny bit more ISP than the dry Panther.  But it's pretty minor, and does not make up for the Panther's other advantages.  Don't think I've ever used the Wheesley apart from fiddling around with a VTOL idea once.  

[KerikBalm]

3 hours ago, The Dunatian said:

aside from its ... reverse thrust capability the wheesley has no real advantages

This is a major advantage. For a plane operating on another world, the ability to back up is wonderful - particularly when you don't want the goliath. It also menas you can mount it on the front of a nacelle with its thrust reversed... twice the engine for similar drag. Can reverse on the ground, power steer while taxing (engines on one side forward, engines on the other side backward)

 

Quote

The panther is more fuel efficient, produces more thrust, and has less mass than the wheesley.

The panther is not more fuel efficient. In dry mode its Isp is 9000 compared to 10500.

It only produces more thrust in wet mode. In dry mode the Wheesley engine has a superior TWR (lets not talk mass or thrust, but the ratio).

When the panther does have a better TWR - wet mode - its quite a bit less fuel efficient. It would consume 262% as much fuel to produce the same amount of thrust if both engines were throttled to have the same level of thrust.

Another question might be why do we even have the panther if we have the turboramjet which has the same Isp and can get planes much faster... but I see enough value in its specifics to keep it - just as I do for the wheesley

[vitekc45c]

The main probem I see with J-33 is that its exhaust does not affect other crafts, unlike the other jet engines, and as such it cant be used to build turboshaft-based aircraft.

[Allocthonous]

I could see making it lighter, maybe. The Panther weighs less but includes an afterburner and vectored thrust? Either reverse thrust is hugely inefficient or the panther should at least cost more for those fancy composite materials making it so light.

It's probably fine the way it is, though. I use it frequently in early career games, and it's well balanced for its spot in the tech tree.

[Whisky Tango Foxtrot]

2 hours ago, KerikBalm said:

This is a major advantage. For a plane operating on another world, the ability to back up is wonderful - particularly when you don't want the goliath. It also menas you can mount it on the front of a nacelle with its thrust reversed... twice the engine for similar drag. Can reverse on the ground, power steer while taxing (engines on one side forward, engines on the other side backward)

 

The panther is not more fuel efficient. In dry mode its Isp is 9000 compared to 10500.

It only produces more thrust in wet mode. In dry mode the Wheesley engine has a superior TWR (lets not talk mass or thrust, but the ratio).

When the panther does have a better TWR - wet mode - its quite a bit less fuel efficient. It would consume 262% as much fuel to produce the same amount of thrust if both engines were throttled to have the same level of thrust.

Another question might be why do we even have the panther if we have the turboramjet which has the same Isp and can get planes much faster... but I see enough value in its specifics to keep it - just as I do for the wheesley

The Panther is useful because it can operate in both modes. A Wheesley will be more efficient than  dry mode and a Whiplash will give more thrust than wet mode, but the Panther lets you do both with one engine.

I like to use it on planes that need to gather high-altitude science. Use dry mode to conserve fuel as you travel to the location and then switch to wet mode for the climb.

[KerikBalm]

I know, I didnt say that the panther is useless.

Its dry mode is generally inferior to the wheesley. Its wet mode is generally inferior to the whiplash.

That doesnt make the panther useless, nor does the usefulness of the panther mean that the wheesley and whiplash have no niche

[KerikBalm]

1 hour ago, Allocthonous said:

 Either reverse thrust is hugely inefficient or the panther should at least cost more for those fancy composite materials making it so light.

Ummm the panther has no reverse thrust. One suggestion makes the wheesley worse, one makes the panther worse... this seems confusing as it seems you present then as equivalent options to penalize the panther?

14 minutes ago, Whisky Tango Foxtrot said:

Whiplash will give more thrust than wet mode

Static thrust is identical at sea level... the velocity curve is similar below mach 2. The whiplash produces more thrust only at higher altitudes and speeds... which is genetally the point of using wet mode... but not always (vtol for example)

The panther in wet mode has the best static asl TWR. Thrust to cross section ratio is also important... and the dry panther generally sucks there - a pair of inline wheeskeys can do quite well for supercruise, but due ti ther thrust curve, they have a lower max cruising speed than the dry... but its much easier to get them past mach 1... just not to 500 m/s+ like you can do with the dry panther (but such supercruise panther designs arent very useful)

[Daniel Prates]

The weesley also consumes less fuel, proportionally to the thrust generated (according to the specs in ksp wiki). If you want cheap a jet for those lazy missions, like landing on the polar caps to collect surface science, ir can be a better choice. 

[ExtremeSquared]

5 hours ago, KerikBalm said:

This is a major advantage. For a plane operating on another world, the ability to back up is wonderful - particularly when you don't want the goliath. It also menas you can mount it on the front of a nacelle with its thrust reversed... twice the engine for similar drag. Can reverse on the ground, power steer while taxing (engines on one side forward, engines on the other side backward)

They greatly reduced the reverse thrust in a recent update. Still useful for STOL planes built for fun.

[KerikBalm]

citation? I don't see a record in any of the recent updates:

http://wiki.kerbalspaceprogram.com/wiki/1.2

I just tested it, and you seem to be right, I flew a plane with a pusher on one side, and a puller on the other... despite the thrust numbers being the same, I had to decrease the thrust on the pusher to 68% to get it to fly without a yaw... cool, I didn't know that was changed.

Well, drag differential mattered, so I made a wheeled vehicle with 4 wheesleys mounted al lthe same direction, 2 reveresed (one on each side). Of course it will slowly start to roll forward on the runway with no engines on.

With the pushing ones set to 70.5, and the reversed ones to 100%, it ever so slowly rolls backwards. At 71% it moves forward again at about the same rate as gravity would roll it,

So these two tests indicate thrust reversal generates roughly 70% of the forward thrust.

Edited February 22, 2017 by KerikBalm

[ExtremeSquared]

A couple updates ago, it was near 100% in reverse.

[TheKorbinjer]

I use the wheesley because it looks cool on certain replicas.

also, because the relative constant thrust at certain altitudes/speeds. It's pretty handy sometimes

Edited February 22, 2017 by TheKorbinger

[regex]

Yeah, what's the isp and thrust regime look like? The Panther is great for small, slow, low-flying planes and looks the part; last thing I want to see on a puddle-jumper is some military-jet-style engine.

[The_Rocketeer]

21 minutes ago, regex said:

Yeah, what's the isp and thrust regime look like? The Wheesley is great for small, slow, low-flying planes and looks the part; last thing I want to see on a puddle-jumper is some military-jet-style engine.

Think I fixed this for u.

Wheelsey = Shire Horse
Panther = Arabian Racehorse,

They're different animals for different things.

[regex]

58 minutes ago, The_Rocketeer said:

Think I fixed this for u.

Ah, yeah, probably, I don't pay much attention to the new names they've given the engines, I'm too old school for that.

[KerikBalm]

3 hours ago, ExtremeSquared said:

A couple updates ago, it was near 100% in reverse.

I know... and until today I assumed it still was (even if it is a bit ridiculous). When did they lower it?

23 minutes ago, regex said:

Ah, yeah, probably, I don't pay much attention to the new names they've given the engines, I'm too old school for that.

I would still call it the basic jet if I wasn't worried that people would confuse that with the Juno ( =0.625m lowest tech level jet).

Although... given the changes to the model, thrust and altitude curve, jet parameters in general, the addition of the reverser and removal of gimbal.... it bears little resemblance to the old school basic jet.... one might as well forget all the pre-1.0 engine names except the Rapier.

[InterCity]

It's amazing for STOL aircraft thanks to the reverse thrust. I use it for surface samples on Kerbin - the short stopping distance reduces the probability of explosions upon landing.

 

[ExtremeSquared]

1 hour ago, KerikBalm said:

I know... and until today I assumed it still was (even if it is a bit ridiculous). When did they lower it?

Not exactly sure. I noticed when my previously-working STOVL plowed nose first into the ground at 40m/s during the VL part. To be fair, 100% absolutely was unreasonable.

Edited February 22, 2017 by ExtremeSquared

[sal_vager]

I'm not aware of any change to reverser thrust, and testing here shows the same thrust from the Wheesley whether the reverser is active or not, I would suggest you check how much drag the engine is developing with aero debug info enabled in the action menu.

Edit:

Looks like any reduction in thrust isn't reflected in the part menu, and it really is nerfed

[Nittany Tiger]

I use some of the weaker engines to provide my current spaceplane with a bit of cross-range capability without adding too much launch mass, but I use the Juno, not the Weesley.  This is not an SSTO, but launches vertically.

There are two more Junos on the top right above the bottom ones.

I would think Weesleys could be used in a similar way, providing non-SSTO spaceplanes some cross-range capability just in case you miss the KSC on re-entry.  The inclusion of reverse thrust is a bonus as well.

I personally haven't found much use for the Panther.  Maybe it's because I don't really have a need or interest in atmospheric planes except for contracts on Kerbin, but even with the contracts I get, the Panther doesn't fill a role the other engines I have fill better.  I thought maybe you could make a primitive SSTO with the Panther, but I haven't played with it enough to see that.  

I actually would love to see if you could make SSTOs with Weesleys or Panthers or even Goliaths because it seems like for space enthusiasts like myself, the only way to do an SSTO is with a Whiplash or RAPIER, which makes most of the jet engines a waste of science (and funds) in the career mode if your main interest is in space exploration.

Of course, like @Snark said, many of the parts in KSP are made to be just useful in the early game and never again, so maybe the Weesley is one of these a stepping stone parts used to obtain a better jet engine later in the game.

[ExtremeSquared]

Here's a plane that can take off and land purely on the difference between reverse and forward wheesley thrust. There is a discrepancy in reported drag values. Thrust values reported as identical. I assumed devs made this change deliberately, because it makes more sense this way.
Edit: Just realized a mod that messes with stock engine stats is installed, but this was the behaviour before that mod was installed as well.

Edited February 22, 2017 by ExtremeSquared

[KerikBalm]

2 hours ago, sal_vager said:

I'm not aware of any change to reverser thrust, and testing here shows the same thrust from the Wheesley whether the reverser is active or not, I would suggest you check how much drag the engine is developing with aero debug info enabled in the action menu.

Well, I just did the test with 4 engines, two reversed, two not reversed... the net result was that the non reversed ones pushed the plane forward. According to the info box, they were both producing the same thrust, yet it wouldn't roll backwards until I reduced the thrust on the ones pushing forward to 70.5%.

I was investigating behavior from a stationary position, so drag values shouldn't matter.

Is the thrust now angled perhaps, and what I'm seeing is cosine losses?

[sal_vager]

1 hour ago, KerikBalm said:

Is the thrust now angled perhaps, and what I'm seeing is cosine losses?

Possibly, if you change this line in the Wheesley's cfg file.

exhaustDamage = False

To True, you'll be able to figure out which angle the thrust is blocked at by placing parts around it and seeing what gets damaged by heat.

Now I think the Wheesley needs changing, back to 100% reverse thrust...

Oh and the Panther is the only jet with 10 degrees of vectoring, which is nice for stunt planes.